Regulated power supply



Dec. 22, 1953 P. H. WELLS ETAL 2,663,759

REGULATED POWER SUPPLY Filed May 31, 1951 4 sheets-sheet 1 Dec. 22, 1953P. H. wELLs rs1-AL 2,663,759

REGULATEU POWER SUPPLY Filed May 3l, 1951 T LL.

4 Sheets-Sheet 2 nun.. "VV" FIG. 2

MAQ l O ff) v 1 AC SOURCE JNVENTORS P. H. WELLS Al A. sTElNMETz BY -w.o. CANNON AT ORNEY Dec. 22, 1953 P. H. WELLS ETAL l REGULATED POWERSUPPLY 4 Sheets-Sheet I5 Filed May 3l, 1951 Dec. 22, 1953 P. I-I. wELLsETAL REGULATED POWER SUPPLY Filed May 3l, 1951 4 Sheets-Sheet 4 ,I Ios|06 Ioo fIoI To CONTROL loa/s /`98 GRID oF TUBE 42 N04 |03) L T YV Acsouncz -QT \R To RscTIrII-:R z; NEGATIVE Q ;:*\l8 TERMINAL N A -Ie I7ARTIFICIAL LINE INVENTORS P. H, WELLS A.A. STEINMETZ BY wo. CANNON WAMATTORN Y Patented Dec. 22, 1953 UNITED STATES PATENT OFFICE REGULATEDPOWER SUPPLY Application May 31, 1951, Serial No. 229,194

16 Claims. 1

The present invention relates to shore station apparatus for submarinecables having submerged electronic repeaters incorporated therein, andmore particularly to regulated power supplies for operating submergedrepeaters.

As indicated in the copending application of H. F. Wilder, Serial No.229,146, filed May 3l,

- 1951, addition of a repeating amplifier in a submerged portion of asubmarine cable circuit provides a number of advantages, such as a largeincrease in the permissible speed of telegraphic communication over thecable.

A submerged submarine cable repeater requires for its various circuits adirect current which is supplied to it over a cable conductor from thenearer shore station and which returns through earth. A typicalsubmerged repeater might require, for example, a direct current in theorder of 6.32 ampere at a voltage of 125 volts. Under normal conditions,an equal additional current is drawn by the terminal artificial line. Inthe example assumed, the shore station power supply might have toprovide a current of 0.64 ampere at an operating potential of 400 volts,275 volts being dissipated in cable circuit resistance and @.32 amperefiowing through the articial line.

For continuous stable operation, the direct current supplied to therepeater should be kept substantially constant, preferably within i0.5%.The power supply should be able to supply this substantially constantcurrent despite large variations in commercial alternating currentpotential and potential differences between the sea earth and theshore-end earth as high as 300 volts. This latter potential, which maybe in either aiding or opposing polarity, is termed an earth potential.With an aiding earth potential of 300 volts in the example assumedabove, the supply voltage would have to reduce to approximately 60 voltsand deliver a current of about 0.4 ampere in order to maintain therepeater current constant. With an opposing earth potential of 300volts, the supply voltage must increase to approximately 740v volts anddeliver a current of about 0.92 ampere.

in order to reduce electrolytic erosion of the submerged repeatercasing, the shore station power supply should be operated with apositive ground connection, applying the negative potential to the cableconductor. It is also desirable that a single cable conductor be usedfor both repeater operating current and signaling current, as the costof providing an additional conductor in the same cable or a separatecable is very high.

Accordingly, it is an object of the invention to provide a regulatedpower supply circuit for a submarine cable submerged repeater.

More particularly, it is an object of the invention to provide a powersupply ior a submarine cable submerged repeater having a substantiallyconstant current despite variations in input a1- ternating potential andvarying earth potentials.

Another object of the invention is to provide a regulated power supplyfor a submarine cable submerged repeater having a grounded positiveconnection.

lfurther objects of the invention will appear from the followingdescription.

In accordance with the invention, these 0bjects are achieved byproviding a series connected current stabilizer having an impedancevalue controlled as a function of the output current and voltage and adirect voltage supply having an output controlled as a function of theimpedance value of the current stabilizer.

The invention will now be described in greater detail with reference tothe appended drawings in which:

Fig. 1 is a block diagram illustrating a controlled power supply inaccordance with the invention;

Figs. 2 and 3 show in greater detail the arrangement of Fig. l; and

Fig. 4 illustrates a modification of a portion of the arrangement ofFigs. 2 and 3.

Referring now to the drawing and more particularly to Fig. l, there isshown one end of a submarine cable I9 having a submerged repeater IIincorporated therein. The positive terminal of repeater I I is connectedto sea earth I2, while the negative terminal thereof is connected to acable conductor I3 interconnecting repeater il and the shore station. Avariable voltage generator I4 is shown interconnecting sea earth l2 andthe shore station ground I5. Generator I4 represents the earth potentialwhich may be poled in either direction and which may have a magnitudevarying between 0 and 800 volts or more. 4

The shore station illustrated is preferably the receiving terminal forthe cable, but may also be the sending terminal. Conductor I3 iscoupled, at the shore station, to one terminal of the cable bridge Bthrough a resistor R. The opposite terminal of bridge B is coupled toground through a resistor I 5 and an artificial line Il'. Theseterminals of bridge B are connected to the shore station signalingapparatus I8. Apparatus i8 is, m turn, connected to aland line. Apex Aof bridge B is connected to the negative terminal of a. controlledrectifier circuit ll through a negative bus N. The positive terminal ofrectifier I9 is coupled to ground through positive bus P. Positive busF-hasa variableimpedance absorption regulator interposed i therein.

The output voltage of rectifier I9 is controlled, in a manner to be setforth more fully hereinafter, as a function of the impedance ofabsorption regulator 20. The impedanceiofabsorption regulator iscontrolled as -.a function of .the voltage betweenbus N and ."grhundb'yr'a voltage controlled stabilizer circuitZl Yand-as afunction of thecurrent flowing through -resistor vEby a current controlled stabilizercircuit 22.

The circuits and operation of rectifier I9, regulator 20 and stabilizers2| and?? willbeA explained more fully hereinafter in connectionvvithzFFig. 2.

Rectifier I9 is supplied with power from an A. C. sourcethrough atransformer :23.

fAs indicated hereinbefore, .the shore station power supply `must'furnish .to repeater il over cable conductor vI3 a direct .currenthaving a predetermined value substantially vindependent of vvariationsin magnitude and polarity of earth @potential and Vvariations .inmagnitude of the commercial voltage source. Absorption regulator 20'provides 1a variable impedance `in series with Vpositive vbusfl?. Thevalue of this impedance is varied -by voltage controlled .stabilizer 2lin a sense'to oppose changesin voltage of bus N with .respect to ground.The value of vthe impedance is also varied bycurrentcontrolledstabilizer 22 vin a sense to oppose any'change .in current throughresistor. R.

-It is evident that with .a'high-value of .aiding earth potential, theAcurrent .through regula-tor 20 will be relativelysmall. On the otherhand, with a high value kof .opposing earth potential, the currentthrough :regulator'2'l willbe relatively large. To reduce .the widerange of current nvalues `,through regulator v20, `the .output voltageof rectifier I9 is controlled as a function-of the voltagedropacrossvregulator ,-20 `in a sense to f aid .themaintenanceof constant. currentthrough resistor R.

The .power `supply Vwill now be described in greater detail withreference to Figs..'2 and 3 wherein reference characters-identical withthose in Fig. 1 denote-like elements.

AIn Fig-.2, A.the :source of direct voltage-for the repeater comprises-a Yfull-wave :grid-controlled .thyratron `.rectifier circuit includingthyratrons 30 and 3i. '.Theanodes ofthyratrons 30 and 3| are connectedto.respective .ends of the secondary 'vlin'dingof power .transformer23 andtothe respective cathodes of ydiodes 3`2 and 33. The .an'ofdesofdiodes-i `and33 .are connected to negative bus N. '.Thecathodes ofthyratrons 30 and 3'! are .connected tothe center tap of the sec-.-ondary winding of ja. grid .control transformer 34 andto a terminal"35 of a'bridge circuit36. The grids of th'y'ratrons"30 and 3| areconnected'to respective lends of Lthe secondary winding of transformer34. The grid control of .thyratrons `30 "and3l willbe "described morefully hereinafter.

The foura'rms of bridge circuitt comprise, re- ;spectively,vr'esistors3'l, v38 and 39, andthe anodecatho'de discharge `path of atetrode E0. "The junction of -resistor'l`39 and the cathode of tube l0is connectedto ground. .Asit is evident that the-bridge circuitvvilllhaveto carry a relatively large current, tube-.40may'be.replacedby a plurality of parallel connected tubes. In a typical 'isconnected to ous N.

and t5 and a voltage regulator tube 4l',

4 embodiment of the invention, resistors 3l, 38 and 3% were given valuesof 40, i0 and 1000 ohms, respectively, while tube all! was replaced byeight parallel connected 807 type tubes. The values of circuit paramersand the tube types given above vand to belrnentioned hereinafter aregiven 4for purposes of illustration only'andare not to be considered aslimiting. The operation of bridge circuit 35 will be described morefully hereinafter.

vNegative 'bus N is connected to apex A of cable bridge B. Between bus Nand ground is con- 'necteda series circuit comprising a voltage regu-`substantially.constant direct potential through resistor H24. Thepositive terminal of source PI Tube lli establishes a reference level atthe cathode of tube 42. The junction of resistors c3 and 5d is coupledto'negative bus N through series connected resistors This latter seriescircuit, together with resistor 44, constitutes voltage divider circuitapplying variations in potential Vof bus N to the anode of tube 52. Theanode-cathode potential of tube f3.2 is also varied directly withchanges in potential of N Whichare-applied to the cathode thereofthrough voltage regulator .tubeit The cathode of atetrode 4B isconnectedto bus N. The anode of tetrode 48 yis coupled to the controlgrid of .tube 'llt through a resistor 0 and to the positive groundthrough a resistor 50 andresistors l5 vand te. VThe screen grid of tubeit is .coupled to bus N through a capacitor all and'to the junction ofvoltage regulator tube il and resistor @t through a resistor t2. Thecontrol grid of tube 'l is connectedtothe anodeof tube 42.

Any tendency for the potential'of bus Nto increase, i. e., become morenegative, will result in a greater voltage drop across tube 5,2, makingthe anode pctentialthereof more positive and reducing thenegativeYblason the grid of tubell. A reduction in grid bias of tube $8 willincrease the anode current ow thereof, thereby increasing the voltagedropacross resistor til and increasing the negativeeias on vthe controlgrid of tube t0. An increased control grid bias on tube 60 increases theimpedance thereof, thereby tending to reduce the voltage of bus N to itsformer value. If thepotential of ous N had tended to decrease, i. e.,become less negative, the impedance of tube il@ would have beendecreased, resulting in an increase in potential of bus N to its formervalue. rPhe effect of variations in impedance of tube 'F50 "on therectified output voltage will'be described more fully hereinafter.

A resistor R, in series with the cable circuit, is used to Vprovide avoltage proportional to the cable current. The voltage developed acrossresistor R is appliedto the control grid of an amplifier tube 53 througha variable resistorfl .and resistors 55 and ie end of resistor R remotefrom the control grid of tube 53 is connected to the positive terminalof a source of potential P2, which positive terminal is `also coupled tothe anode of tube :'53 through a resistor 5l and to one end of a voltagedivider network comprising series connected Yresistors 5s, 59, 50, 6land t2. The cathode of tube 53 is connected to the junction ofYresistors 5S andl and is coupled vto the .negative to the junction ofresistors 58 and 59, thereby maintaining the screen grid at a suitablepositive potential with respect to the cathode of tube 53. .Alternatingcurrents are shunted around source P2 by a capacitor 65.

The anode of tube 53 is coupled to the control grid of anotheramplifying tube 66 through series connected resistors El and 68. Thecontrol grid of tube is coupled to the negative terminal of source P2through resistor 68 and a resistor 69. The cathode of tube 66 isprovided with a suitable biasing potential through resistor 62 suitablybypassed by a capacitor la. The screen grid cf tube Ge is provided witha positive operating potential by connection thereof to the junction ofresistors t9 and E The anode of tube 66 is coupled to the positiveterminal of source P2 through a resistor 1|.

The anode of tube e6 is also coupled to the control grid of lhaseinverting tube 'l2 through a resistor 13. The cathode of tu'be 'l2 iscoupled to the negative terminal cf source PI through a resistor le,while the control grid thereof is coupled to the negative terminal ofsource PI through a resistor l5. The anode of tube 12 is coupled tonegative bus N through a resistor 16, the cathode thereof being placedat a suitable negative potential with respect to the anode by source P|.The

anode of tube 72 is also coupled to the negative terminal of source Plthrough a, voltage divider network comprising resistors H and 18. The

' junction of resistors TI and 18 is coupled to the control grid of tube42 through a resistor 19. The

control grid of tube 42 is by-passed with respect l to alternatingcurrent by a capacitor 80 intercoupling the control grid and cathodeelectrodes of tube 42.

It will be noted that tubes 53, 66 and 12 are connected in D. C.amplifier arrangement so that f the direct voltage across resistor Rproduces a voltage at the control grid of tube 42. An increase of directcurrent in the Cable circuit will increase the voltage drop acrossresistor R, decreasing the bias of tube 53 and consequently lowering theanode potential thereof. The lowered anode potential of tube 53 producesan increased bias for tube 65, thereby increasing the anode potentialthereof.

The increased anode potential of tube 66 is applied to the control gridof tube 'l2 which is operated as a phase inverter with less than unitygain to offset the effects of potential swings across the cable-apex armof bridge B. The increased potential applied to the grid of tube 'I2lowers the anode potential thereof, thereby raising the bias on thecontrol grid of tube 42 and increasing the effective impedance of tube42, As a result, the anode potential of tube 42 will rise, decreasingthe bias on the control grid of tube 48 thereby decreasing the anodepotential of tube 48. The decrease in anode potential of tube 48 appearsas an increase in negative bias on the control grid toc'urrent'var'latlonstubei acts as an ampliner.

As indicated hereinbefore, an increase in potential of bus N or currentthrough resistor R will produce an increase in impedance of tube 4S.This increased impedance will tend to balance bridge 36, thus allowingless current to now in the control winding of a saturable reactor 8|connected across bridge 36. The control Winding of the saturable reactoris connected in series with a rectifier 82 which serves to preventreverse action of the circuit.

A transformer 83, having a tapped secondary winding 84, feeds currentfrom the A. C. source to a load circuit comprising the A. C. Winding ofsaturable reactor 8| and a resistor 85. The grids of thyratrons 3U and3|V receive an A. C.-poten tial from transformer 34, the primary windingof which is connected between the tap on the secondary winding 84 andthe junction of resistor 35 and the A. C. winding of saturable reactor8|.

The smaller current flowing through the control winding of saturablereactor 8| decreases the saturation thereof increasing the reactance ofthe A. C. winding, thereby increasing the reactive component of thevoltage drop thereacross. This in turn causes an increase in the phaseangle between the thyratron plate and grid voltage, decreasing thethyratronconduction interval and consequently the direct potentialdelivered to bus N. Thus, the tendency for the cable current to increaseis compensated by an increase in impedance of the ground return paththrough bridge 36 and a decrease in voltage of bus N. When the cablecurrent tends to decrease, the reverse action occurs, i. e., the phaseangle between the anode and grid voltages of thyratrons-30 and 3|decreases, thereby allowing the thyratrons to increase the directpotential delivered to the cable.

As indicated hereinbefore, changes in earth potential require changes'inpotential of bus-N to maintain constant cable current. Because tube 42appears in the voltage stabilizing circuit as an impedance element,variations in potential of bus N will be repeated thereacross in a senseto maintain the potential of bus N constant. However, when changes incurrent through resistor R require changes in potential of bus N tomaintain the current through resistor R constant, the impedancepresented by tube 42 will be varied by the current stabilizing circuit,thereby permitting the required change in potential of bus N. In thismanner undesired changes in potential of bus N, which might be caused,for instance, by variations in the A. C. supply, will be compensatedwhile necessary changes in potential of bus N, which might be required,for instance, because of variations in earth potential, will beeffected.

Signal currents present in the cable circuit will not affect theoperation of the control sysinm because of the shunting action ofcapacitor In Fig. 4, which illustrates a modification of the currentstabilization circuit of Figs. 2 and 3, circuit elements correspondingto elements in Figs. 2 and 3 are given like reference characters.

The ends of resistor R are connected, respectively, to contacts and 9|.Armatures 92 and 93 of an oscillating relay 94 are caused to makealternately with contacts 90 and 9|, respectively, and with contacts and96, respectively. Relay 94 is connected to the A. C. source, so thatarmatures 92 and 93 vibrate at the frequency of the A., C. source.Armatures 9,2.and93 are connected 2&7 vto :respective terminals ref satcahacitcr :91, awhile contacts 95 and 96 are connected to respective`terminals of :arcapacitor n.98. rQapacitor :38 isshunted-:bygarhigh.leakagerresistance 9.9.

When armatures:;9.2'.-and 93:ar.e,ma.de with (conchange appreciablyonl-ywitlncharlges in-,current v through rcsistorfR.

:One 7Aterminal -..of .fcapacitor 98 :fis coupled :to .ground, Wh-ile fthe other .terminal thereof v.is .coupled zto :the .control-grid :of anelectron discharge tube-l00xthroughrarnesistor-i l Thegcon- V:trolgridofitubeam l'is coupledftogground through a highresistance-Z.Theicathoderoftuberl'il is coupled to tground .throughxarbiasingresistor: W3 suitablycbyepassedzbmaccapactorM14. Theanode of tubef.lzisffcoupled .'.tofa ssource-ofg-positive po- Y* tential.throughzarresistor :105 wand -to 'ground through a voltage adivider:network :comprising resistors |06- and Hl'l. :The.'junetion-fofrresistors l-G fand lill is.coupled;tmthercontrolligridgofztube v42. fflnychangezincurrent@throughsresistorR Iwill .cause al change..in pctentialfacross.capacitor. Changes.- in; :potentialiacrosscapacitoreziarerrey peatedvat` the controlfgridfgof :..tube :1109. Eur linv stance if the.currentrthrough;:resistorzRziwere to increase, thepotentialiacrossnzcapacitor: ggwould increase, decreas-ingrthe 'negative#bias con fthe .controlggridvof tube; H10. ./Assairesult; theaanodepotential of :tubel00'fwillzzdroD-Whichttdrop Will be repeated fatthecontrol;:gridzof:tubeili,i` thereby tending to lower.v the :currentthrough :resistor 5R in amanner `ldescribed hereinbefore.

.ltfisfevident;that:.the contrlrcircuit described in f. connection with.'Eig. 4 ais -rnct :directly 1 connected-Atorthe::cableeircuitzandzhence' is; not@ sub- .jected 1totheihigh:negative 'potentials .fapplied ato: thetcable,

AWhile xthe invention thas ibeen described Lin :particularaembodimentsthereofeandfina particullanuseitgisvnot;desiredthatit' bei-.limitedthereto, ffor. obvious 'modications "fthereo'f 4vvill:occur-.Ito

. 'those lslr-il-lediin f theaartwvithout TdepartingA vfrom :the-.spiritAarid-scope off the linvention as-set forth intheappendedeclaims.

` What is claimedy isz l. A. direct current fpower--supply vfcrfsupply-1 ing :ai substantially constant predetermined rcur- Yrent f to falsubrnergedrepeater interposed in a submarine cable circuithavingamgroundrreturn andY being '.subj ectedfto varying-earthpotentials, :comprisingfafsourceof'alternating-:currentpower, I. a'full-@Wave-gridecontrolled thyratronrectier circuit coupled to saidsource of alternating current L1povversand.v havingfafpl-uralityfof-Athyratrontubes arranged to deliver-aidirectvoltage;'circuitmeans forapplying.saidrlirect-voltage in' negative polarity to saidfsubmarinecablecircuit; a rstiimpedeanceneinvork:.arranged in'the' for-In of`a--normally :unbalanced :bridge circuitfor applying 'said ldirectzvoltage z in :positive "polar-ity #to said ground freturn, s' said.bridge s circuit "having `-in f one l branch :thereof itheridischargerpath fof a l'rst lelectron @discharge tubegmeans Jtofzapply :altriggering 4sig- :nalgto thefjgridsiof saidthyratron'v'tubes, 'meansdresponsiretdthefdegreezot? balance ffsaid bridge a rst value thereof;a;resistiveV elementinterposed .in said-submarine cable-circuit, 'meansto4 derive @from saidI resistive element avr second control; po-

;tential, rf'means -to amplify said `.second control potential and toapply said second ,controlipotentiar to .the-control ,gridof-saidssecondjelectron dischargetube to vary thev `impedancetherefofproportional-.to variations in direct Ecurrent flow .through:saidresistiveelement,v said variations infimpedance of said secondelectron disf Vclfiarge tubeproducing variationsA in magnitude of wsa-id.-rst `controlpotential proportional to said ,variations' in directCurrent through said resistive element thereby to lstabilize .saiddirect voltage at f a'second valuethereofat which the direct currentilovv:throughssaid submarine cable circuit isst- 1b- .sta-ntially equalto z-sad lvpredetermined .value thereof.

1 2. A direct currentgpower supply; for supplying asubstantiallyconstant. predetermined currentto .f a submerged repeat-er interposed;inf ai submarine .cable r circuit having afigroundareturn-fandl beingvvsubjected to Avarying earth potentials,Vv comprising a source ofalternating current power,a'.full wave grid-controlled ,thyratronrectifier 4circuit coupled :to said .source `of 1 alternating .currentpower .-a-ndyihavingyai plurality; ofv thyratron tubes :arranged todeliver adirect voltage-circuit means forz applying,r said directvoltage in negative po- .larity to saidv submarinevcablecircuit, a rstvimr -pedancenetwork varranged in the form. of av nor- -mally-unbalancedbridge circuitgfor applying said direct voltage; injpositive polarityto. said ground returnssaid bridge circuithaving inone'branch thereofthe discharge pathrofa rstelectrondis- 4charge tube,-.means toVderive-ia triggering signal fromsaid source-or alterna-tinggcurrentpower. and to apply. said triggeringfsignal to. the grids ofsaid...thyratron tubes, means-comprising a saturable ,i reactorv havingya.direct current winding 1 coupled t.to A.said bridge. circuitandranalternating. current -.-wind=ingl :coupled l; to vthe grids ofsaid thyratron t.tubes-and.being responsive to=.the;degree of .bal-.ance-,of 4saidzbridge. circuit to-varythephase of .y said 1 triggering'signal thereby to vary the -value of saidt ,direct voltaganavsecondfimpedance network-comprising the l,discharge path ofasecondelectron discharge tube and beingcoupled be- ..t.\veen,said circuitmeans .and saidgground return, V meansto derive. from .said secondimpedance net- .Wo'rk afirst controlpotential propcrtionalto. the

value ofvsaiddirectvoltage, meansto apply said rstcontrol potential tothecontrol grid of. said Jlirst electron discharge tube in asense tovary the impedance thereof and the degree of balance of--said bridgecircuit, proportional to ,variations vinvsaid directvoitage thereby tostabilize said -ff'direct-voltage-at al rst 1value thereof, a resistive.-velement interposed in said submarine cableV cirf cui t,. means toderivefromsaidfresistive element :za-second controlpotential, means toamplify-said second control potential and to apply said second controlpotential to the control grid of said second electron discharge tube tovary the impedance value thereof proportional to variations in directcurrent iiow through said resistive element, said variations inimpedance of said second electron discharge tube producing variations inmagnitude or" said first control potential proportional to saidvariations in direct current through said resistive element thereby tostabilize Said direct voltage at a second value thereof at which thedirect current flow through said submarine cable circuit issubstantially equal to said predetermined value thereof.

3. A direct current power supply for supplying a substantially constantpredetermined current to a submerged repeater interposed in a submarinecable circuit having a ground return and being subjected to varyingearth potentials, comprising a source of alternating current power, afull-wave grid-controlled thyratron rectifier circuit coupled to saidsource of alternating current power and having a plurality of thyratrontubes arranged to deliver a direct voltage, circuit means for applyingsaid direct voltage in negative polarity to said submarine cablecircuit, a iirst impedance network arranged in the form of a normallyunbalanced bridge circuit for applying said direct voltage in positivepolarity to said ground return, said bridge circuit having in one branchthereof the discharge path of a first electron discharge tube, means toapply a triggering signal to the grids of said thyratron tubes, meansresponsive to the degree of balance of said bridge circuit to vary thephase of said triggering signal thereby to vary the value of said directvoltage, a second impedance network comprising the discharge path of asecond electron discharge tube and being coupled between said circuitmeans and said ground return, means to derive from said second impedancenetwork a rst control potential proportional `to vthe value of saiddirect voltage, means to apply said first control potential to thecontrolgrid of said first electron discharge tube in a sense to vary theimpedance thereof and the degree of balance of said bridge circuitpropor ional to variations in said direct voltage thereby to stabilizesaid direct voltage at a first value thereof, a resistive elementinterposed in said submarine cable circuit, means to derive from said.resistive. element a second control potential, means comprising atwo-stage direct coupled cascade amplifier circuit having the controlgrid and cathode electrodes of the rst stage coupled respectively toopposite ends of said resistive element to amplify said second controlpotential, means comprising a phase inverting stage having the controlgrid thereof coupled to the anode of the second one of said amplifyingstages and the anode thereof coupled to the control grid of said secondelectron discharge tube to apply said second control potential to thecontrol grid of said second electron discharge tube to vary theimpedance thereof proportional to variations in direct current ilowthrough said resistive element, said variations in impedance of saidsecond electron discharge tube producing variations in magnitude of saidfirst control potential proportional to said variations in directcurrent through said resistive element thereby to stabilize said directvoltage at a second value thereof at which the direct current ow throughsaid submarine cable circuit is substantially equal to saidpredetermined value thereof.

4. A direct current power supply for supplying a substantially constantpredetermined current to a submerged repeater interposed in a submarinecable circuit having a ground return and being subjected to varyingearth potentials, comrising a source of alternating current power, afull-wave grid-controlled thyratron rectifier circuit coupled to saidsource of alternating current power and having a plurality of thyratrontubes arranged to deliver a direct voltage, circuit means for applyingsaid direct voltage in negative polarity to said submarine cable, afirst impedance network arranged in the form of a normally unbalancedbridge circuit for applying said direct voltage in positive polarity tosaid ground return, said bridge circuit having in one branch thereof thedischarge path of a lirst electron discharge tube, means to apply atriggering signal to the grids of said thyratron tubes, means responsiveto the degree of balance of said bridge circuit to vary the phase ofsaid triggering signal thereby to vary the value of said direct voltage,a second impedance network comprising the discharge path of a secondelectron discharge tube and being coupled between said circuit means andsaid ground return, means to derive from said second impedance network afirst control potential proportional to the value of said directvoltage, means to apply said first control potential to the control gridof said first electron discharge tube in a sense to Vary the impedancethereof and the degree of balance of said bridge circuit proportional tovariations in said direct voltage thereby to stabilize said directvoltage at a nrst value thereof, a resistive element interposed in saidsubmarine cable circuit, a first capacitive element, a second capacitiveelement, relay means coupled to a source of alternating currentpotential alternately to couple said first capacitive element acrosssaid resistive element and across said second capacitive element therebyto produce a charge across said second capacitive element proportionalto the voltage drop across said resistive element, a third electrondis-Y charge tube having the cathode and control grid electrodes thereofcoupled respectively to opposite terminals of said second capacitiveelement, means to derive from the anode of said third electron dischargetube a second control potential having a value proportional to thecurrent flow through said resistive element and to apply said secondcontrol potential to the control grid of said second electron dischargetube to vary the impedance thereof proportional to variations in directcurrent flow through said resistive element, said variations inimpedance of said second electron discharge tube producing variations inmagnitude of said rst control potential proportional to said variationsin direct current through said resistive element thereby to stabilizesaid direct voltage at a second value thereof at which the directcurrent flow through said submarine cable circuit is substantially equalto said predetermined value thereof.

5. A direct current power supply for supplying a substantially constantpredetermined current to a submerged repeater interposed in a submarinecablecircuit havinga ground return and being subjected to varying earthpotentials, comprising a source of alternating current power, afull-wave grid-controlled thyratron rectifier circuit coupled to saidsource of alternating'current power and having a plurality of thyratrontubes arranged to deliver a direct voltage, circuit means for applyingsaid direct voltagein negative poattacca 1r' larity to saidsubmarine'cablaarirstimpedance network arranged in the'for-m ofano'rrnally 'unf balanced bridge circuitfor applying said direct voltagein positive polarity-'to Isaid ground return, said bridge circuit havinginlone branchthereof the discharge path of `a rst electionrdischarge'tube, means toapply'atriggering-signal to the' grids of saidl thyratrontubes, means responsive to the degree of balance of said bridge circuitto vary the phaseY of said triggering signal thereby to varythe value oisaid' direct voltage, a second impedancenetwork comprising the dischargepath of Aa second electron discharge tube and being coupled between'said circuit means andsaid'ground return, means to derive from saidsecond impedanceln'etwork a nrst control potential proportional to thevalue ofsaid direct voltage, means ltoapply' said rst control potentialto the control grid of saidrst electron discharge tube in a sense tovary the impedance thereof and the degreeof balance of said bridgecircuit'proportionalv to variations in said direct voltage thereby tostabilize-said direct voltage at a nrst value thereof, a resistiveelement interposed in said submarine cable' circuit, means to derivefrom sa'id resistive element a second control potential having? ai valuesubstantially solely proportional to theY voltage drop across saidresistive element, a third electron! discharge tube, means to apply saidsecondcontrol voltage to-the control gridv o f said third electrondischargetube, means intercoupling the anode' of said third electrondischarge andthe control grid of said secondl electroni discharge tubeto apply said second control'potential to the control grid of saidsecond electroni discharge tube to vary the impedance thereofproportional to variations indirect current now through'V said resistiveelement, said variationsin impedance' otsaid second electron dischargetube producing variations in'niag'nitude of saidrst control potentialpro'- portionalv toA saidl variations in direct current through saidresistive element thereby to stabilize said direct voltageati'af--second value thereof at which the direct current 'flowthroughsaid submarine cable circuit is substantially equal to saidpredetermined value thereof.

62 A direct current power supply for supplying aV substantially constantpredetermined current tol a submerged repeater7 interposed in' asubmarine cable circuithaving' a ground return and being subjected to'varying e'arthf potentials, compising' a source of alternating' currentpower, a full-wave grid-controlledthyratron rectiner circuit coupled `tosaid source of alternating'current power and' having a pluralityv ofthyratrontub'es arranged to deliver va'dire'ctvoltage,- circuit meansforapplying said directvoltage in negative polars ity to said submarinecable, alrst impedance' net'- work arranged inv the form ofa' normallyunbalanced bridge circuit for applying said' direct voltage in positivepolarity to' said ground return, said bridge circuit having in'onebranch thereof the discharge path of a rst-felectrondischarge tube,meanstol apply a'triggering signal to the grids of said'thyratron tubes,means responsive to the' degree of. balanceof saidvbridge circuit tovary the phase ofV said triggeringv signal thereby toY vary'the value ofsaid direct voltage, a second impedance network comprising the dischargepath of .a second electron discharge tube and being coupled between saidcircuit means and said ground return, means to derive from said secondimpedance network a first control potential proportional to thevalue'ofiV said direct voltage;V means 112 to'apply vsaidflrstcontr-'olpotentialtolthe'.control grid' of Y saidfiirst electron'vdischarge. tube yin a senseto vary" the impedance'thereof vand the degrec 'of' balanceroflsaidbridgeicircuit proportional to variations insaid' direct voltage thereby to stabilize said dire'ct'vo'ltage ata'first value thereof, al resistive-'element' inter-posed in saidsubmarine: cable f circuit, meansl to derive from said resistiveelementals'econdlcontrol potential having avalue=substantially solelyproportional to the voltagel drop acrossI said resistive element, meansto'apply saidsecondcontrol potential to the control grid-of saidsec'ondelectron discharge tube to vary the impedance thereof proportionalto'variationsinldirect-currentflow through said resistive elernentysaidvariations in impedance or: said'second electron-discharge tubeproducing variations in-magnitudefof` said first control potentialproportional'to said variations in direct current throughy said.resistivey element thereby to'-stabilizefsaidtdirectvoltageat a secondvalue thereof at' whichlthe y'direct' current now throughsaid'submarinecable circuitis` substantially equal to'said predeterminedvaluethereof.

'7. Adirect current power supply for supplying a substantiallyconstantpredetermined current to asubmerged repeaterinterposedfin asubmarine cable circuit having a ground return and being subjected tovarying earth potentials, comprising a source of alternating currentpower, a fuli-wave grid-controlled: thyratronv rectifier circuit coupledto said sourceof alternating current power and having aplurality offthyratron tubes arrangedto deliver' a directvoltage, circuit means forapplying said direct voltage in negative polarity to said submarineYcable, .a rst impedance network arranged in' the' form oia normallyunbalancedbri'dgefcircuitfor applying said direct voltageirl-.positive-l polarity to said ground return, saidbridgefcircuithavingin` one branch thereofthe discharge path-.of a rst'electron dischargevtube;` means J toY apply al triggering signal tothe grids of*`saidthyratrontubes, means responsive to-thefdegree` ofbalance of saidbridge circuit to vary the'pha'se oflsaid triggering signal therebyto'vary theva'lue of said direct voltage, a second impedance? network'comprising the discharge pathl cfa second electron discharge tube andbeing' coupled" between; said. circuit means and said ground'v return;means to. derive from saidsecondimpedance' network' a first controlpotential proportional.A to the'fvalue ci` saidV direct voltage,means toapply saidrst control potential to thevcontrolgrid of said' rst electrondischarge' tube'- ina sense to' vary4 the impedance value thereofa'nd'thedegre'e ofrbalance of said bridge` circuit proportional;tofvariationsin said direct' voltage: thereby to stabilize said direct voltage aty afirst-.value thereof, a resistive elementfinterposed in saidfsubmarinecable circuit, means tofderive'from said resistive 4element a secondcontrol potential, means' to amplify said second controll potential andto apply said second control potential to the control grid of saidsecond electronzdischarge 'tubeto' vary the impedance thereof'proportionallto variations in current flow throughI saidresistiveelement, means to suppress'variations in impe'danceofsaid secondelectron' discharge tubek produced by signalling currents in saidresistive element', said variations in impedance of said: secondelectrondischarge tube producing. variationsv in magnitude of' saidfirst control potential proportionalI to said variations indirectcurrent through: said resistive element thereby to stabilize said directvoltage at asecond value thereof at which the direct current flowthrough said submarine cable circuit is substantiallv eoual to saidpredetermined value thereof.

8. A direct current power supply for supplying a substantially constantpredetermined current to a submerged repeater interposed in a submarinecable circuit having a ground return and being subjected to varyingearth potentials, comprising a source of alternating current power, afull-wave grid-controlled thyratron rectifiei` circuit coupled to saidsource of alte-rnating current power and having a plurality of thyratrontubes arranged to deliver a direct voltage, circuit means for applyingsaid direct voltage in negative polarity to said submarine cable, afirst impedance network arranged in the form of a normally unbalancedbridge circuit for applying said direct voltage in positive polarity tosaid ground return, said bridge circuit having in one branch thereof thedischarge path of a first electron discharge tube, means to apply atriggeringl signal to the grids of said thyratron tubes, meansresponsive to the degree of balance of said bridge circuit to vary thephase of said triggering signal thereby to vary the value of said directvoltage, a second impedance network comprising a voltage regulator tubeand the discharge path of a second electron discharge tube and beingcoupled between saild circuit means and said ground return, means toderive from said second impedance network a first control potentialproportional to the value of said direct voltage, means to apply saidfirst control potential to the control grid of said first electrondischarge tube in a sense to vary the impedance value thereof and thedegree of balance of said bridge circuit proportional to variations insaid direct voltage thereby to stabilize said direct voltage at a firstvalue thereof, a resistive element interposed in said submarine cablecircuit, means to derive f from said resistive element a second controlpotential, means to amplify said second control potential and to applysaid second control potential to the control grid of said secondelectron discharge tube to vary the impedance thereof proportional tovariations in direct current flow through said resistive element, saidvariations in impedance of said second electron discharge tube producingvariations in magnitude of said first control potential proportional tosaid variations in direct current through said resistive element therebyto stabilize said direct voltage at a second value thereof at which thedirect current iiow through said submarine cable circuit issubstantially equal to said predetermined value thereof.

9. A direct current power source for providing a substantially constantpredetermined current to a load circuit of varying back potentialcomprising a direct current power supply of relatively low internalimpedance including exciting means for regulating its output, a sourceof primary control potential comprising a bridge network traversed byoutput current from the said power supply and having a variableresistance element in one arm thereof, a source of secondary controlpotential comprising a shunt impedance network disposed across theoutput of said power supply and said bridge network and having avariable resistance element in one arm thereof, a source of tertiarycontrol potential comprising a series resistor in the output of saiddirect current power supply, means for applying said primary controlpotential to said exciting means to regulate the output of said powersupply, means for applying said secondary control potential to saidvariable resistance element to change the resistance thereof, and meansfor applying said tertiary control potential to said shunt impedancenetwork to modify the output of said source of secondary potential,whereby the output voltage of the said power supply applied across thesaid shunt impedance network together with said tertiary controlpotential applied thereto produces said secondary control potentialtherein, thereby to establish a value of said variable resistanceelement to determine the resistance thereof to the flow of outputcurrent from said power supply, and concurrently to develop a primarycontrol potential of a size and sign to produce a regulated outputvoltage from said power supply which will maintain a substantiallyconstant direct current flow in the said load circuit.

10. A direct current power source for providing a substantially constantpredetermined current to a load including a submarine cable circuithaving an electronic repeating amplifier interposed in a submergedportion thereof, said submarine cable circuit being subjected to varyingearth potentials, comprising a direct current power supply of relativelylow internal impedance including exciting means for regulating itsoutput, a source of primary control potential comprising a bridgenetwork traversed by output current from the said power supply andhaving a variable resistance element in one arm thereof, a source ofsecondary control potential comprising a shunt impedance networkdisposed across f the output of said power supply and said bridgenetwork and having a variable resistance element in one arm thereof, asource of tertiary control potential comprising a series resistor in theoutput of said direct current power supply, means for applying saidprimary control potential to said exciting means to regulate the outputof said power supply, means for applying said secondary controlpotential to said variable resistance element to change the resistancethereof, and means for applying said tertiary control potential to saidshunt impedance network to modify the output of said source of secondarypotential, whereby the output Voltage of the said power supply appliedacross the said shunt impedance network together with said tertiarycontrol pocurrent from said power supply, and concurrently to develop aprimary control potential of a size and sign to produce a regulatedoutput voltage from said power supply which will maintain asubstantially constant direct current iiow in the said cable circuit.

11. A direct current power source for providing a substantially constantpredetermined current to a load including a submarine cable circuithaving an electronic repeating amplifier interposed in a submergedportion thereof, submarine cable circuit being subjected to varyingearth potentials, comprising a source of alternating Voltage, a directcurrent power supply of relatively low internal impedance includingmeans to rectify said alternating voltage, a source of primary controlpotential comprising a bridge network traversed by output current fromthe said power supply and having a variable resistance element in onearm thereof, a source of secondary control potential comprising a shuntimpedancey networkz'disposecl across; the; outputi ofi said power.:supplyfandisaidibridgenetworkanda haring f aavariablef;v resistanceelement in; one,l arm thereof; a source-,of tertiary-control potentialconiprising a serieszresistor intheoutput of said direct current powersupply, means. for applying said primary control potential` to saidexciting means to regulate the :output of'saidpower supply, means forapplying said secondarycontrol potential to said variable resistance;element to change the resistance thereof; and-means for applyingv saidtertiary controlpotential to said shunt impedance networktomodifytheoutput ofV said source of secondary potential, wherebyA theoutput'voltage of the said power; supplya-pplied-across the said shuntimpedance: network together with said tertiary control potential appliedthereto produces said' secondary control, potential therein, thereby toestablish a value of said variable resistance elementy to determinetheresistance thereof to, theiilowofY output current from saidpower'supply, and concurrently toA develop a primaryicontrolY potential,` ofa: sizeandV sign to produce a.- regulated-output Voltage fromsaid` powersupply whichwill maintaina substantially constant direct. current flowlin the said cable circuit.

12. Av direct current powersourcefor providing a substantiallyconstant-predetermined current to a load including-a submarine cablecircuit ar,F ranged fortransmissionof ltelegraph signals and having anelectronic repeating amplifier interposed in a submerged portionthereof, said submarine oablecircuit being subjected to varying earthpotentials, comprisingv a direct current power supply of relatively lowinternal impedance including excitingimeans for. regulatingits output, asourceof primary control, potential comprising a bridgenetworkitraversed'by output current from. the saidpower supply andhaving a variable resistancezelement inone arm thereof, a sourceofsecondarycontrol potential comprising ashunt. impedance networkdisposed across the output of said power supply andsaid bridge networkandhaying a variableresistance elementJ in'one arm thereof, a`source-of. tertiary control potential comprising a series resistor inthe output of saiddirectcurrent power supply, means for applying, saidprimary control, potential to said excitingv means to, regulatev theoutput. of said power supply, means,fcr applying said sec ondarycontrolpotential tor said variable resistance element to change theresistance thereof, and means for applying said tertiary controlpotential toY said shunt impedance network to modify the output of. saidsource of secondary potential, whereby' the output voltage'of the saidpower'supply applied across the said shunt impedancenetwork'togetherf'with said tertiary control potential applied theretoproduces said secondary control potential therein, thereby to establisha Value of said variable resistance element to determine the resistancethereof to the flow of output current from said power supply, andconcurrently to develop a primary control pote-ntal of a size and signto produce a regulated output Voltage fromsaidpower supply which willmaintain a substantially constant direct current now in the said cablecircuit.

13. A direct current power source for providing a substantiallyconstantv predetermined current to a load circuit coupledbetween a firstpotential bus and ground and having al varying back potential,comprising a transformer source of power, a second potentialbus,avcontrolled direct output OfsaidpOWersupply andv bridge net-v work andhavinganl electron discharge tube in oneA armi there-of, a; source oftertiary control potential: comprising a series resistor output of saiddirect currentpower supply, means fory applying saidprimary controlpotential to said rectifier circuity to regulate. output of said powersupply, means for apply said secondary control potential tosaid disharge tube in said bridgefnetwork. to change t resistance thereon, and.means. for applying ,i tertiary controlpotential to. said discharge e insaid Y shunt impedance network toV modiiy the output of said source; of,secondary potential,` whereby the output voltage of the said powersupply appliedl across ther said shunt in'ipedance networktogether withsaid tertiary controi potential applied thereto producesr said secondarycontrol potential therein, thereby toV establish aresistancevalue ofsaiddischarge path in said bridge network.` to determine the resistancethereof to theY ficw. of output current from said power supply, andconcurrently to develop a primary controlipotential of a size and signto producel aregulated output voltage from said power supply which willmaintain a subst ntially constant, direct current flow inthe loadcircuit.

14. A direct` current power source for providing a substantiallyconstant predetermined current to a loadcircuit coupledbetween a iirstpotential bus and ground and having a varying back potential comprisingatransfornier source of power, a secondpotential bus, a controlleddirect current power supply. of relatively low internal impedancecomprising a thyratron rectiier circuit coupled to the said transformerand to the said bussesV tov produce. a direct output voltage acrosssaidipotential busses, a source of primary control potential comprising.a bridge network traversed by. outputcurrentfrom the said power supplyand having inA one. arm thereof the discharge path ofv at, least one.electron discharge tube, a source of secondary' control potentialcomprising a shunt impedance network disposed across the output ofrsaidpowerV supply andsaid bridge network and having anelectron dischargetube in one arm thereof, a source of tertiary control potentialcomprising aseries resistor in the output of said direct current powersupply, means for applying said primary` control potential to the gridof said thyratron rectifier circuit to regulate the output of said powersupply, means for applying said secondary controlpotential to saiddischarge tube in said bridge, network to change the resistance thereof,and means for` applying said tertiary control potential.toisaiddischarge tube in said shunt impedance network to modify theoutput of said source of secondary potential, whereby the outputvoltageY of the said power supply applied across the said shuntimpedance network tog-ether with said tertiary control potential appliedthereto produces said secondary control potential there1nther eby,-toiestablish afresistance value ofV control said discharge path in saidbridge network to determine the resistance thereof to the ow of outputcurrent from said power supply, and concurrently to develop a primarycontrol potential of a size and sign to produce a regulated outputVoltage from said power supply which will maintain a substantiallyconstant direct current ow in the said load circuit.

15. A direct current power source for providing a substantially constantpredetermined current to a load circuit coupled between a rst potentialbus and ground having a varying back potential comprising a transformersource of power, a second potential bus, a controlled direct currentpower supply of relatively low internal impedance comprising a thyratronrectifier circuit coupled to the said transformer and to the said bussesto produce a direct output voltage across said potential busses, asource of primary control potential comprising a bridge networktraversed by output current from the said power supply and having in onearm thereof the discharge path of at least one electron discharge tube,a source of secondary control potential comprising a shunt impedancenetwork disposed across the output of said power supply and said bridgenetwork and having an electron discharge tube in one arm thereof, asource of tertiary control potential comprising a series resistor in theoutput of said direct current power supply, means for applying atriggering signal as said primary control potential to the grid of saidthyratron rectier circuit means to vary the phase of said triggeringsignal in accordance with variations in voltage drop through andunbalance of the said bridge network to regulate the output of saidpower supply, means for applying said secondary control potential tosaid discharge tube in said bridge network to change the resistancethereof, and means for applying said tertiary control potential to saiddischarge tube in said shunt impedance network to modify the output ofsaid source of secondary potential, whereby the output voltage of thesaid power supply applied across the said shunt impedance networktogether with said tertiary control potential applied thereto producessaid secondary control potential therein, thereby to establish aresistance value of said discharge path in said bridge network todetermine the resistance thereof to the ow of output current from saidpower supply, and concurrently to develop a primary control potential ofa size and sign to produce a regulated output voltage from said powersupply which will maintain a substantially constant direct current flowin the said load circuit.

16. A direct current power source for providing a substantially constantpredetermined current to a load circuit coupled between a firstpotential bus and ground having a varying back poten- Y tial comprisinga transformer source of power, a

second potential bus, a controlled direct current power supply ofrelatively low internal impedance comprising a thyratron rectifiercircuit coupled to the said transformer and to the said busses toproduce a direct output voltage across said potential busses, a sourceof primary control potential comprising a series connected bridgenetwork traversed by output current from the said power supply andhaving in one arm thereof the discharge path of at least one electrondischarge tube, a source of secondary control potential comprising ashunt impedance network disposed across the output of said power supplyand said bridge network and having an electron discharge tube in one armthereof, a source of tertiary control potential comprising a seriesresistor in the output of said direct current power supply, means forderiving a triggering signal from the said transformer and for applyingsaid triggering signal as said primary control potential to the grid ofsaid thyratron rectifier circuit, a saturable reactor coupled to saidrectifier circuit and to said bridge network to vary the phase of saidtriggering signal in accordance with variations in voltage drop throughand unbalance of said bridge network to regulate the output of saidpower supply, means for applying said secondary control potential to thecontrol grid of said discharge tube in said bridge network to change theresistance thereof, and means for amplifying and applying a portion ofsaid tertiary control potential to the control grid of said dischargetube in said shunt impedance network to modify the output of said sourceof secondary potential, whereby the output voltage of the said powersupply applied across the said shunt impedance network together withsaid tertiary control potential applied thereto produces said secondarycontrol potential therein, thereby to establish a resistance value ofsaid discharge path in said bridge network to determine the resistancethereof to the flow of output current from said power supply, andconcurrently to develop a primary control potential of a size and signto produce a regulated output voltage from said power supply which willmaintain a substantially constant direct current flow in the said loadcircuit.

PHILIP H. WELLS.

ALFRED A. STEINMETZ.

WILLIAM D. CANNON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,020,316 Jacobs Nov. 12, 1935 2,037,183 Strieby Apr. 14, 19362,329,010 Spencer Sept. 7, 1943 2,373,208 Trucksess Apr. 10, 1945

